EDIT: Sadly I've actually been playing this, so if anyone wants more details than what I have below, feel free to ask.
OK, so I checked it out, and it's a browser game through and through. That means you're basically clicking stuff and then waiting an hour before you can click more stuff. And then, of course, there are micro-transactions, as in you can buy items to make the game easier.
That having been said, here's a mini-guide:
At the top of your window you'll see three menus:
任務 - missions
戦闘 - battle (PvP)
サブメニュー - sub-menu
When you select the mission menu, you'll see a box that has your current available missions. By clicking the large button in the middle of this screen, you'll use up 任務P (mission points) and slowly increase the 達成率 bar (achievement % bar). When that bar reaches 100%, the mission will be 'complete'. Complete all the missions in one area, and you'll fight a boss (boss fights are simple, there are three buttons, the left one is attack, the middle one is use items, and the one on the right is retreat). Defeat the boss and you'll increase the rank of the missions in your current area. Keep doing those missions and unlock new areas, etc.
A few important things about missions:
必要任務P - How many mission points you need per click for this mission
必要装備 - this displays the weapon your current mobile suit need to have in order to do this mission
経験値 - the experience you'll get from doing the mission (you get this exp per click, not just for completing the whole mission)
資金 - money, as in how much money you'll get for each click on a mission
設計図 - (development) plans, there is a chance that you'll pick up one of these every time you click on a mission. Collect enough, and you'll be able to create the corresponding mobile suit
Now onto the sub-menu (サブメニュー)
The things that will be of concern to you here are
格納庫 - Hangar, upgrade and view your mobile suits here
戦友リスト - friend list, making friends with other people gives you all sorts of benefits, including using their mobile suits in boss battles
機体開発 - MS development, create mobile suits from plans you've collected
When you go to your hangar, you'll see buttons with the word "改造" (remodeling aka enhancing). Here you can spend money you get from missions to increase your MS's abilities. Unfortunately, the only thing you can spend the in-game money on is your MS's weapons. Increasing the actual frame's stats requires a special item that you need to buy using real money.
-In addition to enhancing the suit, you can switch suits by clicking 搭乗 (board) at the bottom of the suit's stat box
-You can only have a maximum of 20 (I think?) suits. Click the 廃棄 (scrap) button to get rid of those you don't need.
When you go to the MS development area, you'll see a list of your plans on the left, with some numbers like "7/10". That shows you how many plans you have and how many you need to develop a certain suit. Once you have enough plans, click the mobile suit and then the "開発する" (development) button at the lower-right. This way you'll be able to create new mobile suits to equip.
In either the hanger or development area, you'll eventually see a screen that tells you how much each MS or improvement costs. At the top will be your total money, and then below that will be "必要資金" (necessary money). This shows you how much you'll have to spend and how much you'll have left over.
As for PvP battles (戦闘), you can do these at your own risk. They allow you to steal plans and money from other players, but of course there is the possibility of retaliation. To make attacks and defend against attacks, you need 攻撃P and 防御P, respectively.
When you click the battle tab at the top, you'll get a list of users you can attack. Their attack power, defense points, level, and how many friends they have will be displayed. When you select one to attack, you'll be shown what plans they have available to steal. Select the plans you want and then confirm to be taken to the battle screen.
On the battle screen there will be a drop-down menu that corresponds to how many 'battle points' you will spend for the attack. In general you want to spend more battle points than they have defense points. If your attack is successful, you can make another or just leave.
The left-hand side of the screen will display messages about your battles. Often times someone will attack you (thus stealing some of your plans). You can click on the message to view their info and retaliate, but chances are it's a stronger player who will outclass you. That's why it's necessary to make friends who will have your back.
Finally there is the matter of stats. At the top of the screen you'll see your name, current exp (complimented by the exp bar), current level, and current money. On the other side you'll see your current mission, attack, and defense points. The timer next to those points tells you how long until your points refill (they refill automatically when you level up).
Beneath the timer tells you how many bonus points you have to spend on increasing your total mission, attack, and defense points. You get bonus points every time you level up, so remember to spend them by clicking "Up" next to the points you want to increase.
For your MS's stats, click "搭乗機体" (boarded MS) at the bottom-right of the main screen.
攻撃力 - attack
防御力 - defense
地形適性 - terrain type (I've only seen space and land so far)